My experience is limited to Glocks, but the ONLY feeding problems I've ever had were with heavier than stock springs (with Glock barrels and all rounds loaded to 1.258-1.260"). My theory is that they just speed up the return to battery so much that feeding suffers. This seems to get exacerbated when using "match" barrels, or anything tighter than factory. Try going back to factory spring weights. Another option would be stiffer mag springs. Many people say they help when using stiffer recoil springs.
Another thought would be extractor tension and tolerance. If your misfeeds are ending up nose-up (which is what it sounds like), perhaps there's something that's keeping the rounds from sliding under the extractor claw smoothly. I would check the extractor for burrs, and possibly do some polishing/clearancing if the rounds do not slide under it easily (since the Glocks feed well now, use them as a benchmark for how they should feel when sliding under the extractor). Another option would be reducing its spring tension.
I would try the factory recoil springs first, then mag springs, then extractor.
If all else fails, a looser barrel might work. This could be achieved through returning to the factory barrel, or through chamber polishing.
EDIT: Also check the breech face for imperfections that might hinder a round from smoothly sliding under the extractor.
Last edited by 21Carrier; 07-26-2011 at 01:37..